How to test a proxy before you rely on it

Setup guide · Last revised Oct 20, 2026

Set the proxy once, so the login stays out of each command:

export PROXY="http://USERNAME:[email protected]:8000"

1. Requests really go through it

curl -s https://api.ipify.org; echo
curl -s -x "$PROXY" https://api.ipify.org; echo

198.51.100.7
203.0.113.24

The first line is your own address, the second the proxy’s. If they match, the proxy is not being used: check that your tool reads the proxy setting at all. If the second command fails, the next step is the error it prints: curl’s proxy errors, or 407 for a refused login.

2. The address is in the right place

curl -s -x "$PROXY" https://ipinfo.io/country; echo

prints a two-letter country code (ours printed FR). Ask for the country you set in the proxy login and check that this matches. Location databases disagree, and a site may place an address differently: check two of them, and the site itself if it shows your country. Why they differ: proxy location accuracy.

3. It rotates, or holds, as the plan says

Run step 1’s proxy command three times in a row:

for i in 1 2 3; do curl -s -x "$PROXY" https://api.ipify.org; echo; done

A rotating gateway should print a different address each time; a sticky session (often set with a session name in the username) should print the same one until its time runs out. Our test proxy has a single address, so it printed the same one three times, as a sticky session would. A plan sold as rotating that prints the same address three times is worth asking the provider about before you scale up. How the two behave: static vs rotating proxies.

4. How fast it answers

curl -s -o /dev/null -x "$PROXY" \
  -w "connect %{time_connect}s  TLS %{time_appconnect}s  first byte %{time_starttransfer}s  total %{time_total}s\n" \
  https://api.ipify.org

connect 0.000107s  TLS 0.019748s  first byte 0.115282s  total 0.115333s

Our test proxy ran on the same machine, so these numbers are a floor, not what a provider’s exits will show; we do not measure providers’ speed. Run it ten times and look at the slowest, not the average; a job waits on its slowest requests. Compare it with the same command without -x.

5. The site you need accepts it

The only test that matters for your job is the site itself:

curl -s -o /dev/null -x "$PROXY" -w "proxy %{http_connect} site %{http_code} size %{size_download}\n" \
  https://the-site-you-need.com/a-page-you-need

proxy 200 site 200 with a size close to the page’s real size is a pass. A 403, a 429 or a small 200 means the site does not accept this address type or this pace: 403, 429, 200 OK but blocked. Try 20 or 50 requests at the pace your job will run: one success says little.

What not to test with

Do not paste your proxy login into a website that offers to check it: that site then holds a working login to a plan you pay for. Everything above runs on your own computer. Free “proxy checker” lists of public proxies are a different thing: are free proxies safe?.

Next

Set the proxy in the tool your job runs on: curl, wget, Python Requests. Every error code by who sent it: proxy errors.